1. Technical Field
The present invention relates to a running condition detection device and a running condition detection method and a recording medium for detecting and reporting where the current position is located in a predetermined route.
2. Related Art
In recent years, more and more people have been enjoying running, such as jogging as a daily routine and taking part in a marathon event. A small, global positioning system (GPS)-equipped electronic device that such a runner wears for recording a run course and time is available on the market.
Typical GPS receivers show variations in precision of positional data acquired by the GPS. For example, even when a mobile body from which positional data is to be acquired is running in a straight line, the positional data is acquired at regular intervals, swaying to the right and left of the straight line.
Accordingly, when a moved distance of the runner is measured by taking a difference of the positional data acquired at regular intervals, the moved distance is measured longer than an actual distance.
In order to reduce such an error in the measurement distance, measurement without including great variations in the positional data can be considered by skipping the positional data to be used at preset time intervals or moved distance intervals, the positional data being acquired at regular intervals.
However, for example, when the positional data is skipped in a situation where the runner is passing a street corner, another problem arises that the moved distance cannot be measured in accordance with the corner because the positional data takes a shortcut between before and after the street corner.
A vehicle position correction system that corrects a vehicle position calculated from a detection output of a GPS sensor in accordance with a detection output of a distance sensor and a direction sensor is considered (for example, refer to JP 2010-008095 A).
An on-board navigation system that corrects a vehicle position calculated from a detection output of a GPS sensor in accordance with a detection output of a geomagnetic sensor is considered (for example, refer to JP 05-018773 A).
For example, a marathon course prescribes whether runners must run along a left line, a right line, or a central line on each road included in the course. Accordingly, predetermined distances of marathons, such as a full marathon and a half marathon, are established. A distance from a start position to each check position is established by defining each street corner included in the course as a check position.
In contrast, runners do not necessarily run precisely along the prescribed line on each road in the marathon course. Runners sometimes run in a zigzag direction or run along an opposite line, leading to a gap between the prescribed distance on the course and the runner's moved distance as a natural consequence. Moreover, as described above, the moved distance measured based on the positional data from the GPS receiver that the runner carries, which is longer than the actual distance, does not coincide as-is with the prescribed distance on the course.
Therefore, the measurement precision of the moved distance can be improved by correcting the moved distance measured based on the GPS receiver at each street corner (check position) based on the distance data established in the marathon course along which runners run. For that purpose, accurate detection of each street corner (bend position) on the course is required.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a running condition detection device and method for allowing accurate detection of a street corner that runners run.